Bipolar disorder has a large impact on the social functioning of affected individuals, and one part of this problem, as research has indicated, lies in the difficulty these individuals have in identifying facial expressions and emotions. Recently, a team of researchers examined the abilities of bipolar children, aged 4 through 18, to recognize emotions. Their results, which appear in the March issue of the American Journal of Psychiatry, indicate that deficits in emotion recognition might constitute an important risk factor for bipolar disorder.
The study involved 52 children with bipolar disorder, 24 who who were siblings or children of someone with bipolar disorder and thus at risk for the disorder, and 78 healthy control subjects. All subjects were presented with pictures of both children and adults expressing happiness, anger, sadness, or fear. After viewing the faces for two seconds, they were asked to identify the emotion they had witnessed. Tellingly, those at risk for bipolar disorder made about the same number of mistakes of those with the disorder. Overall, 88.5% of subjects with bipolar disorder and 70.8% of subjects at risk for bipolar disorder made more errors reading the faces of both children and adults than did control subjects. To further analyze their data, the researchers divided the at-risk group into two subgroups: those diagnosed with a psychiatric disorder (only at-risk children with ADHD or an anxiety disorder were included in the study) and those without a psychiatric diagnosis. They found that at-risk children without a psychiatric diagnosis still made more mistakes on average than control subjects, an indication that these other psychiatric conditions were not fueling the children’s mistakes in emotion recognition.
Past research from many of these same researchers has implicated the amygdala in the emotion processing deficits associated with bipolar disorder. In a study published last January in the Journal of Child Psychology and Psychiatry, researchers showed pictures of a variety of faces to 33 children with bipolar disorder and 24 control subjects. The subjects were asked to rate the faces based on emotion, such as how fearful or angry a face appeared, while undergoing an fMRI scan. The researchers observed the ways in which neurons in the subjects' brains communicated during this task, and they found that subjects with bipolar disorder had fewer neural connections between the amygdala and two other areas of the brain important for understanding facial expressions and social situations. A lack of connectivity in these regions could cause an individual to have difficulty reading the facial expressions of others or increase their likelihood of misinterpreting facial expressions, viewing a neutral face as threatening, for instance.
From the results of the most recent study, the researchers suggest that deficits in an individual's ability to identify emotions may be inherited and could indicate an increased vulnerability to bipolar disorder. Further investigation is necessary, and future studies should question whether at-risk children who go on to develop bipolar disorder are more likely to misinterpret facial expressions or emotions compared to at-risk children who do not develop the condition. With a better awareness of how this deficit relates to bipolar disorder, mental health professionals may be able to more accurately identify those with the disorder and begin treatment as soon as possible.
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